【作者】 刘峰；

【导师】 邱家驹；

【作者基本信息】 浙江大学 ， 电力系统及其自动化， 2005， 博士

【摘要】 直接法的最早提出是基于经典模型,为分析方便,进行了网络收缩,只保留发电机内节点,此时模型表述为一组常微分方程。尽管对于经典模型的研究比较成熟,但是由于其模型过于简化,从而造成最终结果误差较大。此外由于网络收缩,因而不能进行整个网络的拓扑能量分析,如计及负荷及发电机等元件特性。论文第二章中回顾了自80年代开始提出的几种主流的结构保留模型,然后对它们进行了理论分析和归纳,并且通过几种不同的理论和方法找出了它们之间的本质联系,最后对其进行了总结和展望。 直接法的研究大致包含两个范畴:一是李亚普诺夫函数的构造;一是稳定域方法的研究。本文第二章基于结构保留模型针对第一个问题进行了分析和探讨。在第三章中基于拉格朗日定理和拉萨尔不变性原理提出了一种新的稳定域方法:一阶上界函数法。文中首先针对均匀阻尼模型推导了构建一阶上界函数法的解析表达式和计算步骤,然后针对3个不同规模的算例系统进行了系列仿真,最后将该方法推广到非均匀阻尼模型。 为改善一阶上界函数法保守性,提高精度,论文第四章基于泰勒定理和拉萨尔不变性原理提出了二阶上界函数法,按照类似的步骤进行了理论推导和仿真分析。结果表明,与一阶上界函数法相比,保守性有所改善,精度有所提高。 本文方法尽管保守,但是严格可靠,而且还避免了计算不稳定平衡点这个传统能量函数法存在的困难。更多还原

【Abstract】 The direct method was presented based on the classical model in the beginning. For convenience the power network is reduced, it just keeps the internal node. The model can be expressed as a group of ODE equations mathematically.Although the investigation about the classical model is comparatively mature, big error may exist because of the excessive briefoess.furthermore, the energy analysis of the whole topology cannot be taken into account owing to the reduction of the power network, for example, the characteristics of the loads and generators can not be added. In chapter 2, the history and its main branches of SPM are reviewed at first, then the SPM was analyzed and induced according to the relevant theories, ultimately the research field of SPM was also prospected.In chapter 3, using the Lagrange Mean Value Theorem and the LaSalle Invariance Principle the author presented a method to construct a closed hyper-ball that strictly resides in transient stability domain. This method is termed the first order upper bounding function method. The author derives the mathematical expression and computational steps of the approximated stability region based on the classical model of multi-machine power systems with uniform and non-uniform damping. Numerical examples are provided.For the purpose of improving the character and increase the precision of the first order upper bounding function method, the second order upper bounding function method is put forth in chapter 4 based on the Taylor Theorem and the LaSalle Invariance Principle, the results reveal that the method in this paper has improved the performance in conservative character in contrast to the first order upper bounding function method.The remarkable merit of these methods is its simplicity and reliability although it is conservative comparatively, and furthermore, the method avoids the difficulty of computing UEP that is essential in traditional transient energy function methods.更多还原